# Copyright (C) 2011 Nippon Telegraph and Telephone Corporation.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#    http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
# implied.
# See the License for the specific language governing permissions and
# limitations under the License.

from ryu.base import app_manager
from ryu.controller import ofp_event
from ryu.controller.handler import CONFIG_DISPATCHER, MAIN_DISPATCHER
from ryu.controller.handler import set_ev_cls
from ryu.ofproto import ofproto_v1_3
from ryu.lib.packet import packet, ipv4, arp
from ryu.lib.packet import ethernet
from ryu.lib.packet import ether_types
from ryu.lib import stplib


class SimpleSwitch13(app_manager.RyuApp):
    OFP_VERSIONS = [ofproto_v1_3.OFP_VERSION]

    # _CONTEXTS = {'stplib': stplib.Stp}

    def __init__(self, *args, **kwargs):
        super(SimpleSwitch13, self).__init__(*args, **kwargs)
        self.mac_to_port = {}
        self.flag_table = {}

    @set_ev_cls(ofp_event.EventOFPSwitchFeatures, CONFIG_DISPATCHER)
    def switch_features_handler(self, ev):
        datapath = ev.msg.datapath
        ofproto = datapath.ofproto
        parser = datapath.ofproto_parser

        # install table-miss flow entry
        #
        # We specify NO BUFFER to max_len of the output action due to
        # OVS bug. At this moment, if we specify a lesser number, e.g.,
        # 128, OVS will send Packet-In with invalid buffer_id and
        # truncated packet data. In that case, we cannot output packets
        # correctly.  The bug has been fixed in OVS v2.1.0.
        match = parser.OFPMatch()
        actions = [parser.OFPActionOutput(ofproto.OFPP_CONTROLLER,
                                          ofproto.OFPCML_NO_BUFFER)]
        self.add_flow(datapath, 0, match, actions)

    def add_flow(self, datapath, priority, match, actions, buffer_id=None, idle_timeout=None, hard_timeout=None):
        ofproto = datapath.ofproto
        parser = datapath.ofproto_parser

        inst = [parser.OFPInstructionActions(ofproto.OFPIT_APPLY_ACTIONS,

                                             actions)]

        if buffer_id:
            mod = parser.OFPFlowMod(datapath=datapath, buffer_id=buffer_id, idle_timeout=idle_timeout,
                                    hard_timeout=hard_timeout, priority=priority, match=match,
                                    instructions=inst)
        else:
            mod = parser.OFPFlowMod(datapath=datapath, priority=priority,
                                    match=match, instructions=inst)
        datapath.send_msg(mod)

    def add_flow2(self, datapath, priority, match, actions, idle_timeout, hard_timeout):
        ofproto = datapath.ofproto
        parser = datapath.ofproto_parser

        inst = [parser.OFPInstructionActions(ofproto.OFPIT_APPLY_ACTIONS,

                                             actions)]

        mod = parser.OFPFlowMod(datapath=datapath, idle_timeout=idle_timeout,
                                hard_timeout=hard_timeout, priority=priority, match=match,
                                instructions=inst)
        datapath.send_msg(mod)

    # stplib.EventPacketIn

    @set_ev_cls(ofp_event.EventOFPPacketIn, MAIN_DISPATCHER)
    def _packet_in_handler(self, ev):
        # If you hit this you might want to increase
        # the "miss_send_length" of your switch
        if ev.msg.msg_len < ev.msg.total_len:
            self.logger.debug("packet truncated: only %s of %s bytes",
                              ev.msg.msg_len, ev.msg.total_len)
        msg = ev.msg
        datapath = msg.datapath
        ofproto = datapath.ofproto
        parser = datapath.ofproto_parser
        in_port = msg.match['in_port']

        pkt = packet.Packet(msg.data)
        eth = pkt.get_protocols(ethernet.ethernet)[0]
        dpid = datapath.id
        if eth.ethertype == ether_types.ETH_TYPE_LLDP:
            # ignore lldp packet
            return
        dst = eth.dst
        src = eth.src
        ipv4_pkt = ''
        ip_dst = 'None'
        ipv4_src = 'None'

        if eth.ethertype == ether_types.ETH_TYPE_IP:
            ipv4_pkt = pkt.get_protocol(ipv4.ipv4)
            ip_dst = ipv4_pkt.dst
            ipv4_src = ipv4_pkt.src

        if eth.ethertype == ether_types.ETH_TYPE_ARP:
            arp_pkt = pkt.get_protocol(arp.arp)
            ip_dst = arp_pkt.dst_ip
            ipv4_src = arp_pkt.src_ip

        actions = []
        ports = datapath.ports

        for port in ports:
            if port == in_port or port == 4294967294:
                continue
            # print(ip_dst)
            if (eth.ethertype == ether_types.ETH_TYPE_IP and (ipv4_pkt.dst.startswith('224.') or ipv4_pkt.dst.startswith('239.'))) or (
                    eth.ethertype == ether_types.ETH_TYPE_IP and dst == "ff:ff:ff:ff:ff:ff"):
                match = parser.OFPMatch(in_port=port, eth_type=ether_types.ETH_TYPE_IP, ipv4_dst=ip_dst, eth_dst=dst)
            elif eth.ethertype == ether_types.ETH_TYPE_ARP and dst == "ff:ff:ff:ff:ff:ff":
                match = parser.OFPMatch(in_port=port, eth_type=ether_types.ETH_TYPE_ARP, arp_tpa=ip_dst,
                                        arp_spa=ipv4_src, arp_tha=dst)
            else:
                continue
            self.add_flow2(datapath, 5, match, actions, 5, 10)

        self.flag_table[dpid] = {"eth_dst": dst, "ipv4_dst": ip_dst, "in_port": in_port}

        self.mac_to_port.setdefault(dpid, {})

        self.logger.info("packet in %s %s %s %s", dpid, src, dst, in_port)

        # learn a mac address to avoid FLOOD next time.
        self.mac_to_port[dpid][src] = in_port

        if dst in self.mac_to_port[dpid]:
            out_port = self.mac_to_port[dpid][dst]
        else:
            out_port = ofproto.OFPP_FLOOD

        actions = [parser.OFPActionOutput(out_port)]

        # install a flow to avoid packet_in next time
        if out_port != ofproto.OFPP_FLOOD:
            match = parser.OFPMatch(in_port=in_port, eth_dst=dst)
            # verify if we have a valid buffer_id, if yes avoid to send both
            # flow_mod & packet_out
            if msg.buffer_id != ofproto.OFP_NO_BUFFER:
                self.add_flow(datapath, 1, match, actions, msg.buffer_id, 60, 300)
                return
            else:
                self.add_flow(datapath, 1, match, actions)
        data = None
        if msg.buffer_id == ofproto.OFP_NO_BUFFER:
            data = msg.data

        out = parser.OFPPacketOut(datapath=datapath, buffer_id=msg.buffer_id,
                                  in_port=in_port, actions=actions, data=data)
        datapath.send_msg(out)
